Table 3. Diagnostic evaluation and outcome of POWV/DTV encephalitis, by county and date of illness, New York, USA, 2004–2012*.
| Category | Data by case no. |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13† | 14 | |
| Patient age, y | 91 | 83 | 70 | 5 | 62 | 77 | 81 | 81 | 9 | 4 | 76 | 73 | 77 | 32 |
| Date of illness | Jun 2004 | Aug 2005 | Jun 2007 | Aug 2007 | Jun 2007 | Nov 2007 | Nov 2007 | Jul 2007 | Jul 2008 | Apr 2009 | Jan 2009 | Jun 2009 | Dec 2010 | Apr 2012 |
| County | Alb | West | Cort | Lewis | Put | West | West | West | West | Dutch | Mad | Put | Put | Dutch |
| LHV |
No |
Yes |
No |
No |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
No |
Yes |
Yes |
Yes |
| POWV MIA | ||||||||||||||
| Acute | Pos | Neg | Pos | Pos | ND | Pos | Pos | Neg | Pos | Pos | Neg | Pos | Pos | Pos |
| Conv |
Pos |
Pos |
Pos |
Pos |
ND |
Pos |
Pos |
Ind |
Pos |
Pos |
Pos |
Pos |
Pos |
Pos |
| PRNT titer | ||||||||||||||
| Acute | 40,960 | 320 | 320 | 20 | ND | 320 | 1,280 | <10 | 10 | 320 | <10 | 2,560 | 5,120 | 1,280 |
| Conv |
40,960 |
1,280 |
320 |
80 |
ND |
320 |
5,120 |
40 |
160 |
2,560 |
40 |
20,480 |
5,120 |
320 |
| PCR for POWV/DTV NS5 gene |
ND |
ND |
ND |
ND |
Pos (brain) |
ND |
ND |
Neg |
ND |
Neg |
Neg |
Neg |
Pos (CSF) |
Neg |
| Lineage | U | U | U | U | DTV | U | U | U | U | U | U | U | DTV | U |
| Outcome |
LADL |
LADL |
Died |
LADL |
Died |
Died |
LADL |
Died |
LADL‡ |
LADL |
LADL |
LADL‡ |
Died |
LADL |
| WNV testing | ||||||||||||||
| ELISA | IgM–, IgG+ | Neg | Neg | IgM–, IgG+ | ND | Neg | Neg | Neg | Neg | Neg | Neg | Neg | Neg | Neg |
| PRNT |
Neg |
Neg |
NA |
Neg |
NA |
Neg |
NA |
NA |
NA |
Neg |
NA |
NA |
Neg |
Neg |
| SLEV PRNT | ||||||||||||||
| Acute | Neg | 10 | Neg | NA | NA | Neg | NA | NA | NA | Neg | NA | NA | Neg | Neg |
| Conv | Neg | 80 | Neg | NA | NA | Neg | NA | NA | NA | Neg | NA | NA | Neg | Neg |
*All tests were done on serum samples except as indicated. POWV, Powassan virus prototype strain; DTV, deer tick virus; Alb, Albany; West, Westchester; Cort, Cortland; Put, Putnam; Dutch, Dutchess; Mad, Madison; LHV, Lower Hudson Valley, MIA, microsphere immunoassay; ND, not done; Pos, positive; Neg, negative; Conv, convalescent; Ind, indeterminate; PRNT, plaque reduction neutralization test; NS5, nonstructural protein 5 gene; CSF, cerebrospinal fluid; U, Unknown; LADL, limited activity of daily living; WNV, West Nile virus; SLEV, Saint Louis encephalitis virus; NA, not available. †Acute-phase CSF POWV IgM+ by MIA performed at Wadsworth Laboratory, New York State Department of Health; convalescent-phase CSF POWV IgM+ and IgG+ by ELISA performed at the Centers for Disease Control and Prevention (PRNT titer 8,192). ‡Imbalance.